Method of making terrazzo floor coverings

ABSTRACT

HAS BEEN SPRINKLED ON, IT IS FORCED INTO THE FIRST LAYER AS BY TROWELING OR THE EQUIVALENT. SUBSEQUENTLY, AFTER THE RESIN IS CURED, THE SURFACE IS GROUND SMOOTH AND BECAUSE THE LARGEST CONCENTRATION OF CHIPS IS NEAR THE GROUND SURFACE, A DECORATIVE, HARD SURFACE IS EXPOSED TO FOOT TRAFFIC.   THIS INVENTION IS A METHOD OF FORMING, IN SITU, A RESINOUS TERRAZZO FLOOR COVERING WHICH IS COMPRISED OF A MIXTURE OF AGGREGATE AND BINDER. IN THE RESULTING FLOOR COVERING A MAJOR PORTION OF THE AGGREGATE MATERIAL IS DISPOSED AT OR IN PROXIMITY TO THE WEAR SURFACE WHICH SERVES TO EXTEND THE USEFUL LIFE OF THE COVERING. THE METHOD INCLUDES MIXING FROM ONE-THIRD TO ONE-HALF OF THE TOTAL AGGREGATE REQUIRED WITH ALL OF THE FLUID BINDER AND SPREADING THE MIXTURE EVENLY OVER A PRECONDITIONED FLOOR WITH A TROWEL; ANY FINES OR FILLERS TO BE USED ARE ALSO INCORPORATED INTO THE FIRST LAYER AS PART OF THE AGGREGATE. IMMEDIATELY THEREAFTER THE REMAINDER OF THE AGGREGATE IS SPRINKLED OVER THE FIRST LAYER. AFTER THE TOP LAYER OF CHIPS OR AGGREGATE

Jan. 5, 1971 M. J. BOIARDI METHOD OF MAKING TERRAZZO FLOOR COVERINGS Filed NOV. 4, 1968 CLEAN SUBSTRATE COAT SUBSTRATE WITH PRIMER MIX A PORTION OF THE RESIN & AGGREGAT E OVER PRIMER LAYER OF MIXTURE INVENTOR. MARIO J. BOIARDI BY yk f mffiZaflfoflmZ AT TOR N EYS.

' APPLY FIRST GRIND SMOOTH I 5 PT S R m D n E WM ..r OOL MECHANICALLY FORCE DRY SPREAD LAYER CHIPS INTO FIRST LAYER United States Patent O m 3,552,988 METHOD OF MAKING TERRAZZO FLOOR COVERINGS Mario J. Boiardi, 2501 Arlington Road, Cleveland Heights, Ohio 44118 Filed Nov. 4, 1968, Ser. No. 772,948 Int. Cl. B44c 1/06 U.S. Cl. 117-27 3 Claims ABSTRACT OF THE DISCLOSURE This invention is a method of forming, in situ, a resinous terrazzo floor covering-which is comprised of a mixture of aggregate and binder. In the resulting floor covering a major portion of the aggregate material is disposed at or in proximity to the wear surface which serves to extend the useful life of the covering. The method includes mixing from one-third to one-half of the total aggregate required with all of the fluid binder and spreading the mixture evenly over a preconditioned floor with a trowel; any fines or fillers to be used are also incorporated into the first layer as part of the aggregate. Immediately thereafter the remainder of the aggregate is sprinkled over the first layer. After the top layer of chips or aggregate has been sprinkled on, it is forced into the first layer as by troweling or the equivalent. Subsequently, after the resin is cured, the surface is ground smooth and because the largest concentration of chips is near the ground surface, a decorative, hard surface is exposed to foot traffic.

BACKGROUND OF THE INVENTION Terrazzo surfaces have been well known for many years. They are formed by spreading a mixture of grout and marble chip aggregate over a substrate and allowing the concrete to harden in situ. This is followed by a grinding down of the protruding large chips of aggregate, to a surface which is relatively level with the concrete matrix, then taking a finer grinding wheel and polishing the total surface area. One of the problems with the large aggregate and concrete is the difficult troweling or smoothing process and the high cost.

Recent practice in the terrazzo floor field has been to substitute a synthetic resin for the grout matrix. In practice, the chips or aggregate are mixed with the liquid resin, applied to the substrate (floor) and troweled as smooth as possible. If necessary, the fioor covering is ground or polished after it has hardened. This has often resulted in percolating bubbles forming in the synthetic resin and being entrapped therein. Another problem is that the resin-chip mixture containing an adequate quantity of chips is so highly viscous that it can be applied and smoothed only with great difficulty, considerable effort and expense. Further, in certain applications the resin does not bond well to the substrate.

This invention proposes to solve these problems by providing initially a more fluid mixture of resin, aggregate and fillers to be spread on the floor and then subsequently applying the remaining chips or aggregate as a layer on the upper surface of the resin. Thereby, the wear resistant chips are disposed on the wear surface and a harder floor surface will be the result. Superior bonding is also obtained.

3,552,988 Patented Jan. 5, 1971 BRIEF DESCRIPTION OF THE INVENTION This invention is a method of making a resinous terrazzo floor covering. The covering itself, after it is completed, will consist of a matrix of resinous material formed in situ and in the upper portion of the resin will be disposed a concentration of chips of a hard material which will serve as the prime wear resistant surface for the terrazzo floor.

The method includes mixing a batch comprising from one-third to one-half of the required chips, fines or fillers with fluid binder and troweling this mixture of low viscosity material onto a floor to form a first layer. Subsequently, the remaining chips are spread over the first layer and mechanically forced into the binder. This is followed by another troweling step to smooth out the surfaces generally.

When the mixture comprising the first layer is applied to the floor, the relatively non-viscous mass flows easily. The first layer is spread and troweled to a thickness approximating the size of the larger chips. The larger pieces of aggregate will contact the substrate and protrude, at most, only a minimum amount above the surface of the binder. These protruding chips offer a rough gauge for measuring the desirable thickness of the finished floor. It is intended that the initially applied layer be approximately the thickness of the larger aggregate.

It is an object of this invention to provide terrazzo floors with a dense aggregate content at the wear surface by a .more eflicient and less expensive method.

It is another object of this invention to provide a method of forming terrazzo coverings in situ by initially applying a resin-aggregate mixture of low viscosity followed by a top dressing of chips which are mechanically forced into the upper surface of the first layer to thereby provide a highly wear resistant covering which is well bonded to the substrate.

Another object of the invention is to provide a method of forming a resinous terrazzo floor covering which has improved adhesion or bond to the floor as compared with prior art methods.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the sequence of procedural steps which are followed in practicing this invention;

FIG. 2 is a fragmentary elevational view, in section, showing the first layer applied to the floor;

FIG. 3 is a fragmentary elevational view, in section, showing a layer of aggregate deposited on the first layer;

FIG. 4 is a fragmentary elevational view, in section, showing the aggregate layer embedded in the first layer; and

FIG. 5 is a fragmentary perspective view, in section, of the finished floor.

PREFERRED EMBODIMENTS This invention was made to overcome a defect in the prior art. A current method of installing terrazzo floors is by applying a plurality of preformed tiles to the floor. This is satisfactory in some situations, however, it has become expensive to lay the tiles because of labor costs and there is a continual problem of the tiles becoming bent, warped and dislodged due to a number of causes. The instant invention is a method of laying a unitary ter- 3 razzo floor in situ, thereby eliminating cracks between tilesWhich collect dirt and other undesirable elements. Also, the floor provided by the instant invention will prevent any possibility of chipping of the edges and lifting of a portion of the covering to present a safety hazard.

Referring more particularly to the drawings, the floor or substrate is first conditioned by cleaning it, insofar as possible, and then applying to the clear floor a coating 12 of primer material which is a bonding agent and serves to provide improved adhesion for subsequently applied resin. After the coating 12 is dried, a mixture of resin 14 and chips or aggregate 16, along with any fines or fillers to be used, are mixed in a batch and applied as a layer 18 over the coating 12.

Many synthetic organic ploymeric resins will be suitable for this type of fioor. For example, the prime resin used may be of the epoxy type, polyester, or many other commercially available resinous materials.

The chips or aggregate may be marble, phenolic resin, alumina, siliceous materials or any other material desired. The only requisite is that the chips be of a relatively hard material since they will serve as the wear or abrasive resistant surface of the floor.

When mixing the batch of material to be applied as layer 18, the quantity of chips 16 mixed with the fluid binder 14 will be from one-half to one-third of the total volume of chips which Will be in the final product. Any fines or fillers to be used are also included in this initial batch and considered part of the chips. Several experiments were done in this area and it was found that when more than one-half of the chips were used in the initial mixture, the resulting heterogeneous mass which is to be troweled onto the coating will be too viscous and lumpy to be easily applied to the floor by the normal troweling method. This is one of the problems in the prior art which this invention has overcome.

By providing only a small percentage of the chips in the initial mixture, the layer 18 flows easily before the trowel onto the primed floor. Because of the relatively liquid nature of the resin as applied, it will make a better contact with the primer coat. This liquid state also reduces bubbles or percolating holes in the resin layer. Troweling of this fluid first layer largely reduces bubbles therein. It will be understood that the chips in the first applied layer of resin rich material will serve as a means to establish a uniform thickness of layer during spreading and troweling.

Immediately after the first layer 18 has been leveled, a layer 20 of the remaining chips is sprinkled or spread thereon. The volume of chips applied to the upper surface of the first layer 18 will be from one-half to two-thirds of the chips in the completed covering. This large percentage of chips near the surface will visibly appear as a high density chip concentration and serve as a wear resistant surface. The applied chips are then mechanically forced into the layer by rolling, rough troweling or some other convenient method for embedding them into the resin binder. It is preferred to trowel the upper surface of the embedded chips to approximately the level of the surrounding mass of resinous material to make a smooth surface.

It was found that when more than two-thirds of the aggregate is sprinkled on the surface of the smooth first layer 18, it is extremely difficult to mechanically force all of the aggregate into the binder. Thus, it has been experimentally determined that the range for the aggregate in the initial mixture should be from one-third to one-half of the amount in the final hardened covering.

oftentimes, the floor must be ground and/or polished to smooth out any irregularities remaining after the troweling has been completed.

While the terminology and drawings used to describe the invention have been limited to a single embodiment, it is not intended that this be a limitation on the invention. Obvious modifications will readily occur to those having ordinary skill in the art. Rather, it is intended that invention be limited only by the scope of the appended claims.

The invention claimed is:

1. A method of permanently affixing a resinous terrazzo covering to a substrate including the steps of:

(a) conditioning and coating the substrate with primer material,

(b) mixing a batch of chips and hardenable resinous fluid binder to form a heterogeneous mass, wherein the mixed chips constitute from one-third to one-half total volume of the chips in the completed covering,

(c) applying a substantially uniform first layer of said mass over the primed substrate, the thickness of the first layer being substantially equal to the thickness of the largest chips within the mixture,

(d) applying the remaining chips to said first layer as a substantially uniform second layer of dry chips; wherein the last mentioned chips constitute from onehalf to two-thirds total volume of the chips in the completed covering,

(e) mechanically forcing the second layer of chips into the first layer of chips and resinous fluid binder,

(f) smoothing the upper surface of the embedded chips and the surrounding mass, and

(g) allowing the fluid binder to harden.

2. The method of claim 1 wherein the primer material is a bonding agent.

3. The method of claim 2 followed by a grinding of the surface of the resin-chip layer to smooth the surface.

References Cited UNITED STATES PATENTS 2,706,936 4/1955 Wilson 11726 2,793,136 5/1957 Root 117-16 2,925,831 2/1960 Welty et al. 117-26 2,948,201 8/1960 Nagin et al 11716 3,062,604 11/1962 Hodgen 11733 3,097,080 7/1963 Weir 117'25 3,360,391 12/ 1967 Richtzenhain 11726 3,446,644 5/ 1969 Murphy et al 11726 WILLIAM D. MARTIN, Primary Examiner R. M. SPEER, Assistant Examiner U.S. C1.X.R. 1l7-l6, 26, 29, 33 

